1. Field of the Invention
The present invention relates to the display of the residual electric energy of a battery of a tuning device which performs a sound-producing function.
2. Prior Art
In a conventional tuning device which displays the charge state of the battery automatically in order to provide a low battery alarm, fluctuations of the current consumed for sound production are large when a reference sound producing mode is selected, and therefore fluctuations of the battery voltage becomes so strong that it is difficult to provide an alarm display by using an IC for voltage detection, A/D conversion, etc. when the voltage drops below a working limit voltage of the battery.